After 1 week, take a blank page. Without looking at the PDF, draw the diagram from memory. Then, check the PDF for accuracy. This is active recall.
If you are looking to master the building blocks of visual art, there are several authoritative resources and blog posts that provide both the theoretical foundation and practical exercises you need. While " Art Fundamentals: Theory and Practice " by Otto Ocvirk is a classic textbook, you can find it and other essential guides through several legitimate free and paid channels. Art Fundamentals Theory Practice Free Download Books Pdf
Copy the book title + "PDF" + "Internet Archive" into Google. Do not click on "ad" links. After 1 week, take a blank page